“There really was only one main target to try to put as a headline speaker at our event, and the reaction has reflected that,” Franks said. “No doubt about it.”

Franks launched the conference last year after a Kickstarter campaign raised nearly $32,000. The event drew about 600 people from around the world. This year, he’s expecting more than double that. It brings together people just starting to experiment with podcasting to those who’ve launched their own programs that listeners can download online.

Podcasting has been around for a decade, but it never had a breakout hit quite like "Serial." Koenig spent an entire year researching the 1999 murder of Hae Min Lee, a popular high school student in Baltimore. Her ex-boyfriend and classmate Adnan Syed was convicted of murder, but he’s maintained his innocence.

The show is a spinoff from the creators of another popular series "This American Life". It developed such a following that Saturday Night Live and Funny or Die parodied it.

“The fact that Serial was a story that went, you know, from episode to episode, and it gave you that cliffhanger at the end of every episode just like television shows ... ” Franks said. “So I think it kind of put that podcast into that TV series mold that we’re used to seeing and we’re used to kind of consuming.”

The weekend-long event will take place at the Omni Fort Worth Hotel starting July 31st. Tickets go on sale Monday at 8 a.m. And podcasting may be free, but this conference isn’t. Price of admission: $297.